1. Field of Invention
This invention relates to a means of managing acreage by use of a center-pivot irrigation system. More specifically, it is directed to an improved, low cost method of controlling grazing consisting of two center-pivot irrigation systems attached at the pivot adjustable to varying angles of separation with both equipped with electric wire for holding in animals, while simultaneously irrigating a crop or pasture.
2. Related Art
Center-pivot irrigation systems have long been used in many areas where irrigation is either necessary or desired to increase crop production. These center-pivot irrigation systems have excelled due to their simplicity of operation and convenient one-pivot water supply, and have yielded quite substantial increases in crop production.
An early effort at a center pivot irrigation apparatus is found in U.S. Pat. No. 3,599,664 to Hotchkiss et al. This patent reveals a center pivot irrigation system mounted on wheels with flexible joints between distributing pipe sections and means for controlling speed or movement of sections based on a signal conveyed by the flexing of the joints.
Another prior effort at an irrigation system is found in U.S. Pat. No. 3,724,728 to Fizmaurice. This patent reveals a boom type irrigation system permanently positioned in a field to be irrigated with no wheels for movement.
A prior art effort to modify a center pivot irrigation system to provide for a means of irrigating closer to the edges of a square field is found in U.S. Pat. No. 3,902,668 to Daugherty et al. This patent adds to prior an by revealing a boom extension to a center pivot irrigation system guided along a path defined by an electrical conductor.
Other pertinent examples of modifications to a center pivot irrigation system are found in U.S. Pat. Nos. 3,912,170 to Reinke, 3,983,898 to Zimmerer et al., and 4,397,421 to Schram. Reinke's patent reveals a lightweight substantially all-aluminum sprinkler system capable of withstanding great variations in temperature. Zimmerer's patent reveals a modification to the couplings between the individual pipe sections of a center pivot irrigation system. Schram's patent illustrates a means of applying liquid chemical to a field utilizing a center pivot irrigation system.
None of the above mentioned prior art utilize a center-pivot irrigation system for controlled grazing. Farmers have allowed grazing in a field where a single center-pivot irrigation system is used. However, management of the herd is labor intensive in such an environment, with over-grazing frequently occurring. This is because the animals tend to concentrate in one part of a pasture until the food supply in that area has been totally consumed, or the plants have been destroyed. Often the animals will eat so heavily that the plants themselves will be destroyed. Even if they move onto another area of the pasture, this results in the area where they have been not recovering adequately. In addition, there is the hidden costs of labor from having to move fences. With the invention described herein, the issue of having to move fences is minimized.
A prior effort to design a means so that livestock do not graze in one area for an extended period of time is found in U.S. Pat. No. 4,721,061 to McNatt. While meeting the objective of avoiding having animals graze in one part of a pasture for an extended period of time, the McNatt patent does so through the use of a labyrinthine path set up so that the rings are of approximate equal square footage. Such a setup would require a great amount of manpower to establish.
Though the above mentioned prior arts have individual qualifies and characteristics, including being helpful in crop production, they can be improved to provide a center-pivot irrigation system that requires minimal setup, minimal labor and thereby greater marketability, as well as at the same time help reduce or eliminate erosion due to overgrazing. Most ranchers understand the need of continuous inspection of their herds and frequent movement of their herds from one pasture to another. The marketing success of an apparatus for controlled grazing requires that the device minimizes labor and costs while maintaining or improving the marketable quality of the animal. The devices referred to by the prior art either do not address the aspects of controlled grazing, or do not truly minimize setup and labor; therefore, the devices tend to be less marketable for the purposes of controlled grazing.